Frequently Asked Questions
How do I know what size anchor I need?
We produce what we call our load chart and this lays out, in a simple format how to self specify anchor sizes based on the project requirements. If you are a domestic user then we have tried to help as much as possible by suggesting items for you on the Uses tab. If you are a commercial user and need a second opinion please give us a call as we are happy to help.
Please have a look here at our Load Charts
Why do you have three different types of spiral anchors?
Spirafix are meant to be versatile products so having three anchor head types makes perfect sense to us. We produce the C type helical anchor that has a solid hexagonal head. These are made for applications where the anchor is to be driven through a slot that is fixed to a structure. We produce an AC type helical anchor which has a threaded head and a B type which has a single hole head.
Can I secure my children's outdoor play equipment using Spirafix?
The current AC type ground anchors cater for this very well. Most play equipment is made from timber so either the 30mm diameter anchors for smaller equipment or the 40mm for larger equipment an be used along with 90° brackets, set screws and coach screws. These come in convenient kits (see Kits under the Products tab) with full instructions. The length that you choose will depend on whether your soil conditions are favourable (undisturbed soil, clay or sandy loam that is not wet would be classified as favourable). It also would depend on the age of the children using the equipment. If in doubt please give us a call and we can advise you.
If cost is an issue then the B type spiral anchors can be used, though these are a little more complicated to fit as the head of this anchor needs to be lined up with the item being anchored to be able to use a screw or a bolt. Generally speaking most users will need to have a short trial and error process to get the hang of them, but as they can be unscrewed very easily it's not an issue. These anchors can be used with a spacer, a 90° bracket or screwed straight onto round tube.
Please take a look at the information on Swing Sets and Climbing Frames
What options do you offer for tethering projects?
The most efficient way of using Spirafix ground anchors for tethering applications is to have the anchor in line with the load. The issue here is that the spiral anchor must be locked off to prevent it from counter rotating back out of the ground under extreme loads. Until recently the way around this was to use an offset tethering bracket that created an angle between the load and the axis of the anchor, usually 30°. The bracket acted as a torque arm that stopped the anchor from unscrewing. This still works and we have a variety of brackets that can either be bolted onto the top of the anchor or the anchor is driven through a slot in the bracket. The downside to this method is that under extreme loads with a sideways pull the anchor can bend. We are now producing locking bars that can be driven in at 90° to the angle of the load to allow the anchor to be in line with it. The locking bar prevents any tendency of the anchor to unscrew itself. We also produce multi anchor hubs that can be used to give much higher load ratings. These are through slot hubs that take either two or three anchors and are quick and easy to use.
Can your anchors be used for 4x4 winch applications?
Yes, you can use our SA454 two or three spiral anchor hub with either SF50-8-0460C or SF50-8-0610C anchors (SF50-8-0490AC and SF50-8-0630AC anchors will also do). You will need to use an M16 shackle fitted to these brackets to be able to use it. You will need a short handled sledge hammer to install the anchors and and a 28mm spanner to remove them.
Do I need to prepare the ground before I install Spirafix Ground Anchors?
No, Spirafix are designed to cope with hard ground conditions and drive down into position on their own helix. They are installed via impact, so they are a hammer in anchor. They are not twisted into position, so normally a lump hammer (for smaller anchors), sledge hammer (medium sized anchors) or power tool can be used. Its important that you know the ground you are using is free from buried services and that you avoid danger. If in doubt do not install until a professional has advised you.
What can I use to tie up my barge on the canals?
The same anchors will work with the same brackets, though the two anchor hub, SA454 would in all probability cope with the loads. The advantage to this system is that the helical anchors do very little damage to the river banks as they are easily unscrewed. Hammer in anchor - twist out.
Please take a look at the information on Barge and Boat Mooring
How do you install the anchors?
Spirafix Ground Anchors are designed to be easy to install - so whether you are a domestic or commercial user their use should be straightforward. You simply drive the spiral anchor into position down through your chosen surface using impact - hammer in anchors. So if you are using a lump hammer, sledge hammer or machine the anchors are driven in and NOT screwed in. They drive down on their own helix so every impact forces the anchor to rotate down into position.
Please take a look at the selection of Installation Tools and Installation Guidance
Can Spirafix be used in tarmac?
They can be used on tarmac. The key here is that a pilot hole needs to be drilled through the tarmac and compacted aggregate underneath it until soil is reached. This hole anywhere from 50% to 75% of the spiral anchor diameter depending on the specification of the tarmac. An SDS Max combination hammer drill is a useful power tool as the hole can be drilled with this and then the drill be changed for a hammer cup and stem that can then drive the anchor in. Our spiral anchors, or helical anchors are impact in / hammer-in, they are not twisted into position.
Can I use Spirafix for a timber building and decking project?
We have had our spiral anchors tested for this application and they are suitable. Spirafix ground anchors will sustain at least the same load when being pushed into the ground as when be pulled out. However, the requirement for a foundation application is that any building load must be sustained over a long period of time. This will cover ground conditions at their weakest, which is during prolonged wet weather. Also clays will have surface heave and shrinkage during these climatic changes. This means that any anchor being used needs to be de-rated for this application and that a sufficiently long enough anchor is used to provide stability. In practice a 50mm diameter by 1 metre long anchor is suitable and load of up to 500kgs per anchor can be expected. The big advantage in using Spirafix anchors is that no concrete is needed, little excavation has to be done and the project can be completed in less time. Our spiral or helical anchors are impact in / hammer-in anchors - they drive down into position on their own helix.
Please take a look at the information available on Timber Buildings and Decking
What size nuts and bolts fit with the different spiral anchor sizes?
Well this one is easy - M10 for 30mm, M12 for 40mm, M16 for 50mm anchors and M24 for the 75mm anchor range. Please call us if you'd help and advice regarding fittings, fixings and brackets for our anchor ranges. Tel 01633 890 910 or email sales@spirafix.com